I seem to recall that later on (in the 3.5 release, I think) he got powered up a little more. As opposed to, say, Shinpi, the darklord of Rokushima Táiyoo, whose curse was being unable to do anything but watch as his children destroyed the empire he'd built.
In terms of him being a copy of a particular archetype, I don't think that Nathan Timothy had one. While his son, Alfred Timothy, was "the wolfman" (in that Alfred loved losing himself to the thrill of the hunt and the vicious dismemberment of his victims, making his darklord curse - that he turns back into his human form if he gives in to his predatory instincts, something he fears his pack finding out about - all the more ironic), Nathan Timothy's desire was simply to indulge his wanderlust and serial killer impulses, something he was still able to do (albeit in a limited fashion) while confined to the Musarde River. If that has a particular gothic inspiration (beyond simply serial killers in general), I'm not sure what it is.
I think Timothy would have been much better served if he was portrayed as a kind of New England/Lovecraft Country fishing boat captain who was secretly a monstrous fishman hybrid who captured outsiders who wandered into his grasp, slaughtering and eating some, and sacrificing the rest to his alien Gods of the Deep (perhaps a Half Kua-Toa in D&D terms?) in the vein of Obed Marsh and the Deep Ones from
The Shadow Over Innsmouth. The recent movie
The Lighthouse with Willem Dafoe and Robert Pattinson is the vibe I'm going for (weird, creepy movie that has lots of great moments but ultimately fell apart, IMO.)
He would be pretty famous locally for keeping the townspeople fed by being assured to always haul in a bountiful harvest of fish, even when all the other captains come back with empty nets (
"Thar goes ol' Cap'n Timothy; ah kin rem'mber when he single-handed kep' awl o' us fed back durin' the drought o' ought fahve! Shoor is strange how he dun't seem to nevah age none, but ah jus' gess that's b'cuz o' all tha' healthy salt watah ayuh he'ez alwuz breathun'.")
(The thick, mangled Lovecraftian/Kingian phonetic New England hick accent is mandatory.)
He would also always have lots of strange golden trinkets for sale that he "finds" in his travels, which he is happy to sell to all comers for a pittance (
"Ah'm a fishahman, not a goldmongah! I jes' peck awl ah these up outta the watah easy as kin be, so ye kin have wun fer jes' fahve peices ah coppah... ") Trinkets that are covered with mysterious alien runes, and give anyone who possesses them
weird, hauntingly inviting dreams of casting off their land-bound mortal existence to revel in eternal ecstasy with strange, tentacled beings in the deep dark waters off the coast.
After a while a number of townsfolk gave-in to the dreams of Timothy's golden trinkets and started interbreeding with the denizens of an unholy Kuo-Toa city just off the coast,
and now a large segment of the townsfolk are secretly Kuo-Toa Hybrids, who all gather to worship at a strange new church that sprang up in the region called the Esoteric Order of the Magna Mater (Blibdoolpoolp.)
Anyway, that was the story I had thought up for him if I ever used him in a campaign, all ready to go with
The Shadow Over Verbrek. It works
much better to my mind than the ill-fitting and shoehorned "werewolf ship captain" idea, which I think just doesn't jibe.